Dronen, et al U.S. Pat. No. 5,454,585 and Kruckmeyer et. al. U.S. Pat. No. 5,690,195 are incorporated by reference herein so that certain details of damper and strut assemblies need not be described in detail herein.
Dampening components used in vehicle shock absorbing systems, including shocks, struts or engine mounts have dampening characteristics which can be varied to adjust the dampening component to desired conditions. Dampers are well known in the prior art. Examples can be seen in Dronen et al U.S. Pat. No. 5,454,585 and Kruckemeyer et al U.S. Pat. No. 5,690,195 (incorporated by reference herein). The dampening characteristics may be varied to account for a number of different factors. These include speed, cornering status of the vehicle, weight distribution etc. Such dampers generally contain adjustable valving, solenoid or other electrically actuable devices.
A relatively new type of adjustable damper is also available. These dampers, magnetorheological fluid dampers, also known as MR dampers, damp shock forces sustained by a vehicle by transmitting the forces to a piston or diaphragm etc. which is pushed through a chamber filled with magnetorheological fluid. An electrical coil adjoins the chamber where the MR fluid is provided. Electric current flowing in the coil varies the properties of the magnetorheological fluid pumped by the piston through an orifice in or adjacent the piston. In this manner, the flow of magnetorheological fluid and thus the amount of dampening, can be controlled.
Generally, the piston that is pushed through the magnetorheological fluid is mounted on the end of a rod within the damper. Electric current is provided to the coil electrically adjustable valving or solenoid from the end of the rod opposite the piston by means of an electrical conductor in the rod. The conductor is electrically coupled to a connector by a coupling assembly mounted at the end of the damper. Generally, the end of the rod protrudes through the damper and receives an electrical connection or plug that delivers power, ground and/or a signal from a vehicle electrical system. When damping characteristics with the damper need to be altered (such as when sensors on a vehicle detect certain preset specified factors such as changes in speed, cornering, etc.) an electrical signal can be sent to the coil, solenoid or adjustable valving in the damper via the electrical coupling assembly.
Dampers, including shocks, struts, and engine mounts and struts may be exposed to water or other contaminants depending on location and orientation of the damper within a vehicle. For instance, certain automotive struts are installed with a piston at the bottom portion of a piston rod, damper rod and located at the bottom portion of the vehicle. The opposite end of the rod then projects through a shock tower opening into the vehicle engine compartment. In other applications, such as to relieve side loads to damper rods, the orientation of the strut is reversed so that the electrical conductor exits the bottom of the rod in an xe2x80x9cupside-downxe2x80x9d position. In such an orientation in a vehicle suspension, the plug or coupling assembly may be fully exposed to moisture dirt or other contaminants not as prevalent in the engine compartment. Such orientation may also find the damper subject to greater physical shocks, including the higher frequencies and amplitudes found at the vehicle wheel rather than those found within the vehicle body.
Particularly in shock and strut construction, the length of the strut is a large factor in its placement within a vehicle. Thus, any reduction in the overall length of the strut system is an advantage. Heretofore, electrical connections have added significantly to the overall length of the damper. Examples of electrical connections in the prior art can be seen in Frances et. al. U.S. Pat. No. 6,007,345 and Frances et. al. U.S. Pat. No. 6,036,500. The ""500 patent shows an electrical connection system to a strut involves placing a large connector on the top of a shock or strut tenon. The connector is placed on the tenon and thereafter an operator locks the connector by twisting a lock ring. The lock ring causes two metal legs to squeeze onto the tenon threads and secure the connector to the shock. However, there is no obvious method to assure that the connector is fully seated. Thus there is no way to ensure that connector has actually made electrical contact with the electrode.
Another electrical connection can be found on what is referred to as a Computer Command Ride (CCR) shock. The CCR shock developed a lip around the very tip of the damper rod that enabled a connector to lock in place. However, the CCR rod is a very large diameter rod which is detrimental to the design since it requires a large diameter piston that affects the overall shock package size, which in turn requires a very large connector body. The design also prohibits the mating of the ground circuit to the outside diameter of the damper rod, which is needed to provide a connection system that does not require rotational alignment before mating. This solution is impractical for most shocks or struts in which the diameter of the rod is small or where space considerations need to be taken into account. Thus, alternatives to the CCR shock connection are necessary.
The known prior art also requires an operator to install an electrical connector using two hands. Therefore, engine compartment design requires a design in which hand clearance for installation must exist. For example, such clearance requirements must be available to twist the lock shown in the ""500 patent. Furthermore, service and maintenance considerations must also be considered. Existing designs do not provide an obvious way to disconnect the electrical connection to service personnel. This can result in frustration or damage to the connector during servicing.
Other methods of attaching a connector directly to a damper rod could potentially degrade the tensile and torsional integrity of the piston rod valve.
Accordingly, it is a feature of the present invention to provide an improved suspension damper which overcomes the disadvantages of prior art suspension dampers by providing a unique interface system which allows both connection of the damper to the vehicle and connection of an electrical connector to the damper in a simplified connection system. The invention can be used with any ride control system that requires power and/or an electric signal to reach the core of a damper including a shock absorber, strut or engine mount.
As used herein, xe2x80x9cdamperxe2x80x9d and suspension damper refer generically to any device used to dampen vehicle vibration, including the aforementioned shocks, struts and engine mounts. The terms shocks, struts and mounts are used interchangeably throughout, but all refer to suspension dampers. The present invention provides a connection to the damper rod/piston rod (also referred to as a shock rod or tenon) provides both signal and ground circuits, has a minimal size, a low insertion force, non-orientation problems, and a retaining system which ensures the electrical connector is retained on the damper during vehicle usage.
The new connector utilizes a fastener (specifically a tenon nut) that is currently being used to secure the damper to the vehicle. The nut is first modified by adding a groove below an end portion of the existing tenon nut. In a preferred embodiment, a chamfer is also added. The connector can be both mated and locked to the tenon nut at any rotational angle in a smooth operation by an assembler using one hand. Since the tenon nut must already be installed to retain the damper (shock or strut) to the vehicle, no new labor operations are required. The modification to the tenon nut provides a groove that accepts a wire clip that is preferably made part of the electrical connector. Mechanical attachment of the connector to the damper strut assembly is achieved by pushing the connector downward onto the modified tenon nut that is also used to secure the damper to the vehicle. As the connector reaches its fully seated position the wire lock (which is preferably integral to the connector) grips the groove of the tenon nut and is secured.
The preferred embodiment also includes a connector position assurance (CPA) member. This portion of the electrical connector is snapped into place to prevent the wire lock from being disengaged accidentally or through vehicle vibration. The wire lock and the CPA provide a positive visual indication that the connector is secure to the damper. The CPA and wire lock can be subsequently disengaged for easy serviceablity to remove the connector from the damper. In addition to the connection system being serviceable, it also provides a positive visual indication that the connector is secure to the damper.
In a preferred embodiment, the tenon nut is an internally threaded coupling nut which resembles a standard nut on the lower external half and has a low angle ramp on the exterior upper end is rotated downward onto a threaded rod of the damper. An exterior annular locking groove is disposed between a low angle ramp (or chamfered) portion and the nut (or tool engaging) portion. The locking groove accepts a wire clip that is part of the electrical connector body and locks these two devices together. The preferred embodiment electrical connection allows power and ground circuits to be electrically connected and secured to the damper assembly. The two opposite ends of the connector are formed at about a 90xc2x0 angle from one another to further allow the connection system to be used in areas with space restrictions. In this embodiment electrical current is delivered to a pin which is isolated from and runs through the center of the damper rod. A ground terminal mates with the damper rod, which is used to complete the electrical path. The system also provides an environmental seal for the electrical interfaces.
These features along with other features, of the present invention are achieved in a suspension damper comprising a longitudinally extending cylinder portion, the cylinder portion including both proximal and distal ends. The damper rod, carried in the damper, extends from the proximal end of the damper. The damper rod includes a bore with an electrode disposed within that bore. A fastener for securing the damper rod to a vehicle is also provided. The fastener is disposed over the damper rod and includes a groove. An electrical connector for supplying electrical power to the electrode is provided and includes a power terminal having at least a first and a second end. The first end is connected to the electrode and the connector is secured to the fastener with a lock which mates with the groove of the fastener. In the preferred embodiment, the perimeter of the nut includes both a tool engaging portion, which resembles a common nut and accepts a tool for rotation, a chamfered portion and a grooved portion therebetween. The lock, in a preferred embodiment comprises a spring wire, which slides over the chamfered portion and is captured within the groove. A position assurance member is removably attached to the electrical connector and the spring wire assuring that the spring wire cannot be disengaged from the damper. It also provides positive visual assurance that the connector is seated properly.
In accordance with another aspect of the invention an electrical connection system is provided which comprises a fastener for securing a damper to a vehicle, the fastener including a groove therein. An electrical connector which includes a power terminal having at least a first and second end for supplying electrical power to the damper is provided. The connector includes a lock which mates with the groove of the fastener. In accordance with a more specific feature of the invention, the lock is a spring lock which includes two legs extending therefrom which cooperate with at least one tab on the electrical connector to open and close the lock. The connection system includes a position assurance member removeably attached to the electrical connector of the spring lock. The position assurance member includes an arm which entraps the spring lock and prevents transverse movement thereof.
In another aspect of the invention an electrical connector body is provided which includes a housing that has at least a first longitudinally extending portion and a second portion extending orthogonal thereto. A conductive ring is located within the first portion and a first power conducting terminal is generally located within the second portion. The first power conducting terminal is releaseably attached to the conductive ring. In a preferred embodiment the conductive ring includes a spring arm which releaseably attaches to the first power terminal, a portion of the first power terminal being molded within the housing.
Yet another aspect of the invention includes an electrical connector body comprising a housing including a first end portion and a second end portion. A first power terminal generally extends between the first end portion and a ground terminal located within an interior cavity of the second end portion. A second power terminal generally extends between the first and second end portions. An environmental barrier including a connector seal is disposed within the interior cavity of the second end portion. A vibration dampener is provided integral with the connector seal. In a preferred embodiment the vibration dampener includes a plurality of legs extending outwardly from the second end portion that come to rest on the top of the fastener when assembled.
Thus, it is a principal object of the present invention to provide an improved suspension damper system which can be easily installed within a vehicle.
Yet, it is another object of the present invention to provide an improved suspension damper system which has a compact design thus requiring less clearance space within a vehicle than prior art designs.
Still yet another object of the present invention is to provide an improved suspension damper connector which provides positive visual assurance that an electrical connection is in place.
Yet, another object of the invention is to provide an improved electrical connection system to reduce the complexity of installation and reduce overall costs.
These and other objects of the invention will become apparent to those skilled in the art upon reading and understanding the following detailed description of preferred embodiments.